Maryland officials wary of Virginia plan to introduce Japanese oysters to bay


Virginia's plan to see if a Japanese oyster can resist a disease devastating the Chesapeake Bay's native species has aroused the objections of Maryland officials, who insist the experiment is fraught with environmental risks.

But a spokesman for the Maryland Department of Natural Resources said yesterday that the agency had not yet decided whether to bring legal action to block the experiment, which Virginia scientists hope to begin in the next 10 days.

A decision is expected in a few days, said spokesman Ray Gould.

In the past, laboratory experiments have shown that the Japanese oyster resists dermo, one of two infections crippling the Chesapeake mollusks. Virginia's catch, hurt even worse than Maryland's, fell to a record low of 40,000 bushels this past season -- compared with an annual harvest in the range of 4 million bushels three decades ago.

Scientists with the Virginia Institute of Marine Scientists say that an experiment to see if Japanese oysters can also resist the other infection, MSX, can be done only in the bay because the disease simply doesn't thrive under laboratory conditions. The infection, not harmful to humans, kills oysters before they grow fat enough to be harvested.

The institute, a division of the College of William and Mary, plans a yearlong experiment in which it will place 300 Japanese oysters and 300 native oysters in trays resting in the York River just east of Williamsburg. Scientists will compare each breed's susceptibility to the MSX disease.

The experiment was approved Tuesday by a 6-2 vote of the Virginia Marine Resources Commission.

But W. Peter Jensen, Maryland's fisheries director, said he fears that the foreign breed could grow out of control and displace native species or spread parasites that could have untold consequences.

Mr. Jensen said he doesn't object to the idea of experimenting with Japanese oysters, but said the tests should be conducted in a "closed system" of bay water kept apart from the Chesapeake itself.

"In a closed system, you can set up a microcosm, dump in natural water, have all the crabs and fish, the whole works," he said. "That's not artificial conditions. We don't think trying it in the wild is going to prove any more than you would learn in a closed system."

Dr. Roger Mann, the principal investigator of the Virginia experiment, said "thirty years of effort" have not shown a way to produce MSX infections in a closed system. Native oysters simply don't get the disease under those circumstances, leaving scientists with no way to measure whether a foreign species is more resistant. What's more, he said the Japanese oysters have been raised in quarantine so they are infection-free, and have been genetically manipulated so they cannot reproduce.

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